The company is one of several developing thin-film solar cells made from the combination of materials copper indium gallium and diselenide (CIGS).

CIGS, one alternative to the dominant silicon solar cell, is fast becoming a substantial piece of the fast-growing solar business. Solar industry research firm Prometheus Institute for Sustainable Development estimates that thin film technology could represent 20-30 percent of solar cell production by 2010.

Nanosolar and Solyndra, another CIGS challenger, are said to be looking to raise significant amounts of money as well at very high valuations, according to rumors. One of the largest venture investments last year was another CIGS producer, Heliovolt.

"It used to be that CIGS technology was the next hope for thin-film PV (photovoltaics), but that point has been reached by Global Solar," Gering said, adding that others will reach that point.

Gering discounted the progress of his competitors. That's not surprising, given that he is trying to raise money, but the company has been manufacturing for a few years already and all of its production for 2008 is already sold.

Until now, the company has sold its cells for use in portable, flexible solar chargers for military use or to charge consumer electronics.

But he said a bigger growth opportunity is in solar panels and building-integrated PV, where cells are baked into roofs or siding. To expand, it needs more capital to build a 40-megawatt plant in Tucson and a 35-megawatt plant in Berlin, Gering said.

In addition, Global Solar claims to hold the CIGS efficiency crown for converting light to electricity.

The company's products can now convert 10 percent of sunlight to electricity and the company claims it will get to 13 or 14 percent.

For comparison, the most efficient silicon solar cells are in the 20 percent range.

About the author

Martin LaMonica is a senior writer covering green tech and cutting-edge technologies. He joined CNET in 2002 to cover enterprise IT and Web development and was previously executive editor of IT publication InfoWorld.
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